function y2 = reduce_labels(y)
    mapping = [1,2,3,4,2,5,5,6,7,8,8,9,10,11,12,13,15,15,16,18,17,14,19,20,20,21,30,29,24,31,33,34,36,32,35,37,26,28,22,23,25,27,28,38,39,39,39,39];
    y2 = mapping(y);
end

